Rear axle hop on heavy throttle accel

[SRQTerry]

I have a 72 Camaro with 1st gen Ride Tech 4 bar link and coil overs in the rear. I recently changed from Chevy 8.5" axle to a Ford 9" axle. It now has a severe axle hop on heavy throttle accels. Drive line angles are equal at front and rear u-joints. What adjustment should I make? Different spring rate or adjust shock settings? (I have single shock rate adjustment)
Thanks for any input.

[TheJDMan]

What spring rate is on the rear? Are the lower bars parallel with the ground? To start, you can try adjusting more damping into the shocks but ultimately you may need to upgrade to a double adjustable shock.

[dhutton]

Most of this discussion applies:

https://www.pro-touring.com/threads/...t=Art+Morrison

Don

[Josh@Ridetech]

Just a few questions:

What exactly are the transmission and pinion angle set at?
When you switched over to the 9", did you change the length of the upper bars?
What spring rate are you using on the shock and where is the rebound adjustment set at?

[79T/Aman]

so all you've done is go from a 10 bolt to a 9"?
re-check you pinion angle and it may need to be changed.
What limited slip differential do you have ? locker?
Was the gear ratio changed?
torsional torque is different on a 9" than a 10 bolt in turn applying the twisting force to the suspension differently

[dontlifttoshift]

torsional torque is different on a 9" than a 10 bolt in turn applying the twisting force to the suspension differently

I think I know what you are meaning to say, but would you mind clarifying that?

Your website traffic would go up if you fixed your signature.

[79T/Aman]

Thanks Donny.
I experienced the same thing in one of my cars, and could not discount the possibility the larger ring gear of the 9" could affect how the pinion gear climbs the ring gear under power regardless of the gear, but a gear change can also affect the amount of torque at the tire and how the suspension is able to cope with it.
I fixed it by adjusting the pinion angle, this was with leaf springs however.

[SRQTerry]

Just a few questions:

What exactly are the transmission and pinion angle set at?
When you switched over to the 9", did you change the length of the upper bars?
What spring rate are you using on the shock and where is the rebound adjustment set at?

Front and rear u-joint working angles are 2 degrees. We put new bushings at the axle end of the UCR and heim joints at the body end like your earlier gen design had. The length is 9 5/8" center to center. The springs are 12" free length, 200 #/inch rate. The shocks are set at 4 clicks from softest setting. FYI these are not your shocks they are Varishock brand. (were on the car when we bought it as was the 4-bar link set up)
How critical is it that the lower bars be parallel to ground? Mine are higher in the front.

I have talked to you on the phone in the past, but not about this specific problem. Thanks for any input you can provide.